The present invention relates to an apparatus and method for rearranging a multi-track succession of rows of containers into a single track or single file stream of containers as the containers are conveyed between the infeed and outfeed ends of the conveyor apparatus. In connection with the process of filling containers such as glass bottles, glass jars, cans, plastic bottles and plastic cans with beverages and food stuffs, for example, there are often situations where the flow of three, four or more containers advancing in parallel need to be converted into a single row stream of containers for being fed individually into a processing machine such as a labeling machine. One of the major problems incidental to this process is that there can be a multitude of collisions between the individual bottles or other containers which result in violation of permissible noise levels. Moreover, the impact between glass containers damages them and occasionally breaks them. This results in reducing the productivity of the container handling apparatus.
A method and apparatus for solving the foregoing problems is described in European patent EPO 085 184. This apparatus comprises an infeed conveyor having belts on which bottles are advanced abreast in rows of four. An intermediate conveyor is arranged contiguously with and in parallel with the infeed conveyor and there is a single lane outfeed or discharge conveyor arranged contiguously in parallel with the intermediate conveyor. Thus, rows of bottles coming in on the infeed conveyor can successively move to the intermediate conveyor and then to the discharge conveyor on which they advance in single file. The intermediate conveyor comprises a plurality of parallel adjacent longitudinally moving conveyor belts driven in the direction of the discharge conveyor in a staggered manner and at high speed. The intermediate conveyor, the infeed conveyor at its terminal area located next to the intermediate conveyor and the discharge conveyor are similarly sloped or slanted transversely to the longitudinal direction at an angle relative to a horizontal plane that induces the bottles to slide over the adjacent conveyor sections as a result of a horizontal force component of gravity. A rail of the infeed conveyor located on the lower side of the slanted conveyor converts into a guide surface in the area around the intermediate conveyor, the guide surface being designed as a supporting surface for the bottles on the lower surface, and discharges to a rail of the discharge conveyor located on the lower side of the slope. The slant of the intermediate conveyor, the infeed conveyor and discharge conveyor in the required area is at an angle of approximately 10.degree. to 12.degree.. As a result of the mutual support between bottles, they are gently and safely accelerated while undergoing lateral transfer on the conveyors under the influence of the gravitational force. The belts of the intermediate conveyor run at increasingly higher speeds as they progress from the infeed conveyor to the discharge conveyor. The apparatus is widely used in bottle filling operations and permits processing up to 110,000 bottles per hour with little bottle wear and an acceptable noise level.
Regardless of the merits of the patented row-to-single file converting apparatus, the high productivity of the apparatus is disadvantageous when used in conjunction with lower capacity container filling equipment such as where a processing capacity of only up to about 20,000 bottles or containers per hour is required. For low capacity systems, the space required for the patented system and the expense in constructing it is considered to be too great. It has, therefore, not been possible previously to benefit from the low noise level and minimal wear and minimal glass breakage features to installations having lower capacities.
European patent EP-B-O 175,292 shows apparatus for converting a multi-row container stream into a single row stream for relatively low rate container handling systems. In this apparatus, the intermediate conveyor and the discharge conveyor are arranged in parallel with each other, and abut entirely and directly on the infeed conveyor. The infeed conveyor, the intermediate conveyor and the discharge conveyor are slanted transversely at an angle of 11.degree.. A rail arranged on the lower side of the slanted infeed conveyor continues in a straight line into the discharge conveyor. The transfer of bottles from the infeed conveyor to the intermediate conveyor and to the discharge conveyor takes place by means of slide plates onto which the containers, such as bottles, are pushed by the infeed container. The bottles are then pushed over the slide plate by the bottles that follow and are taken up by the intermediate conveyor and discharge conveyor in sequence.
The apparatus just discussed has some fundamental defects. If, for example, four rows of bottles arranged in parallel approach the infeed conveyor at a speed of V.sub.in, then the discharge conveyor must exhibit a speed of V.sub.out, which is four times as great as the infeed conveyor speed in order to handle the quantity of containers. If, as is suggested in the cited European patent, the belts of the infeed conveyor and the intermediate conveyor operate at the same speed, the bottles which are pushed from the slide plate at essentially V.sub.0 onto the corresponding transport belt of the intermediate conveyor or the discharge conveyor are accelerated at four times the speed. The path available for the acceleration during this forward push from the slide plate onto the corresponding conveyor belt is, however, relatively short so that acceleration rates are very high at the transfer point. Since the center of gravity of bottles is above the point of contact, which provides the accelerating frictional force, the bottles tip over during an acceleration in the direction toward the infeed conveyor. This tipping action brings about collisions with the bottles that follow so that a very high level of noise develops and there is an increased risk of glass breakage. Furthermore, there is a risk that the bottles will fall off the belt as a result of the tipping movement so productivity is impaired and waste is increased. Even if, as is described in an alternative embodiment suggested in European patent EP-B-O 175,292 the belts of the intermediate conveyor operate at different speeds, these disadvantages are only partially nullified. Thus, the apparatus described in the European patent under discussion has not gained wide acceptance by the industry.